The present invention relates generally to pumps, and more particularly, to a rotary pump especially designed to dispense epoxy or solder paste.
The assignee of the present invention manufactures automatic dispensing systems that employ pumps to dispense fluids, such as epoxy, during manufacturing. One such system is a model 3500 Automatic Dispensing System that is used to dispense conductive epoxy during multichip module (MCM) die and capacitor attachment processes.
A problem that has been found in the epoxy dispensing process is that separation occurs between the binders, the silver and the resin used in the epoxy. The separation of the epoxy is due to the large density difference between the silver particles and the epoxy resin.
Separation is especially severe for conductive epoxy because of the large density difference between silver particles and epoxy resin. When separation occurs, it can cause inconsistency of the bond line thickness, die flatness and thermal dissipation of the multichip module.
Accordingly, it is an objective of the present invention to provide for an improved rotary pump designed to dispense epoxy or solder paste.